Automatic Control Switch - Water Pump

The pictured device is unfamiliar to me, but it looks like more than just a pressure switch, though it might be a differential-pressure flow switch.

A good strategy for your situation would be a flow switch that activates a centrifugal booster pump. Whenever anyone opens a valve, an initial small flow starts the pump, which boosts the pressure to give a more adequate flow. When the valve is closed, there is no flow, and the pump shuts off.

I am also not familiar with this switch but it looks a lot like the flow switch used by Davey Torrium pumps. There also appears to be a diagnostic output on the front of the pump and if you have a manual you may be able to trouble shoot using the indicator lights. The Davey Torrium also has a similar guide and may be of use.

If low flow is because of plugged lines, you may want to assure that the plugging is not increased and flow is poor. You cannot boost water flow if the pump is not receiving water. Hope that helps.

Newbiehandyman.

Thanks for your responses.

There's no clogging with the pipes because the flow is fine when I bypass the control switch and connect the motor pump directly to the power supply.

I do not have a manual unfortunately...I guess these things aren't expensive, might just buy a new one.

I'm also thinking its a timer switch because I can't find any flow or pressure detectors on the switch control...if it is a flow or pressure switch, what can I expect to see on the switch control?

Thanks again. Daniel

On looking again at the pictured switch, I now suspect it is a flow meter/totalizer.

I don't know how its switching logic, if any, is set up, or whether it would fit my earlier suggestion.

If any manual or other clarification is available, it might help.

Sounds like a circuit board problem! Without seeing the specification sheet that came with the Automatic Control Switch/pump, we will be speculating on the problem.

If there is a solenoid valve that 'opens" based on LOW water pressure, the solenoid may not be getting a signal (circuit board). A component may have failed on the circuit board that controls the solenoid? If you can turn that pump and provide a picture of the front of it, we can see the brand name and then look it up on the net.

End result may be that it may be cheaper to purchase another one... Mark

Thanks guys, I'm thinking it is a circuit problem too.

On the circuit board there's a copper "thing" (I can't see because there's some slight brown burn marks on the housing) housed in transparent plastic case.

Would this brown discolouration suggest something's burned out? Or is it normal occurance on circuit boards?

I'll try to get some photos.

Thanks gents.

This observation may be critical in finding the root cause of the problem. Exposing the circuit board may reveal this BURN to be a component failure or a burned out LAND on the circuit board itself. If you are circuit board savy.....you may be able to replace the component or jumper the land yoursef. Cheap and quick fix. Remember Safety!

Haha, I am definitely not circuit board savvy. I'm actually having trouble exposing the whole circuit board because it's stuck down tight in its plastic housing.

But if it's as simple as replacing certain parts then I'm definitely interested in getting my hands dirtier and cracking open the housing to inspect the whole circuit board.

I'd be doing this out of sheer curiosity now since the easiest option would be to get the landlord to reimburse me with the cost of a new switch.

You've infected me with the "knack".

haha thanks again. Daniel

I believe this to be a flow/pressure switch. If the pumps runs but do not switch off when the valve is closed the pressure switch will stop the pump. Obviously the "burnt thing" is a relay that finally gave up. You may open it and replace the relay or replace the unit.

Thanks for responding.

How does the switch detect the flow or pressure in the pump? There's nothing physically touching the water or any sensors in the chamber. The chamber just consists of a cylindrical cone thing in the middle with an opening at the top (that connects to the pipe that leads to a tap) and an opening at the bottom (connects to the motor pump). The openings allow water to flow when the tap is turned on.

I can't figure out how the electronic stuff (the switch) knows when to turn on/off. Is there something magnetic housed inside the cylindrical cone thingy?

I'm leaning towards timer now because I found a manufacturers website which mentions (in broken English) stuff about an exam process.

thanks again, Daniel

if you have very low pressure from your municipal supply (vs well water, your post is unclear on that point), you have a larger problem than simply a bad flow switch. Low water pressure can lead to contamination of the fresh water supply by allowing contaminated groundwater to seep into any leaks there may be in the water main. I would look seriously at your root problem of low pressure before I tried to simply boost the pressure.

Your pictures looks like a Flow Activated Switch and it normally works like this:

1- When you put the power ON, it will start and run for ~15 seconds if there is no demand of water (all taps are closed). This allows the pump to pressurise the system (and a small expansion bladder inside the device==in the right hand side of the picture).

--- If your pump has been primed. If not, it will attempt to prime it if the pump is suitable for that. Also, there should be a foot valve on the bottom of the suction, if sucking from a pit. If the water supply is from mains, then no need for priming.

2- When a tap in the house is opened, the flow of water will trigger the device to energise the pump and keeps it running until you close the tap for 15 sec approx. The system will be pressurised for the next tap opening...

3- There, normally, is a pressure switch inside but this is used to set (or is preset at factory) the minimum pressure... If reached (due to very small leaks that are not detected by the flow switch...) to start the pump and repressurise the system.

Your case: There is normally a reset push-button that you should press to start the device when the red light comes ON. The unit will activate the pump for ~15 seconds at least to repressurise or/and supply an open tap... re-starting the cycles.

*** If this does not start the pump, then the unit might be faulty and needs replacement.

*** If this restarts the pump and supplies water... stops at the closure, then it is OK and you need to look at the installation and the minimum pressure setting (if available...). These units have a limit range for the pressure (or height) they can handle...

I hope tis will help you diagnose and repair

Is the photo just the flow switch or the pump as well? It looks too big to be the switch only. Tornado described the system operation. The switches on eg shower pumps are built in, and quite small. Not sure how they work, but there are a few ways of detecting water flow, including electromagnetic.

Cheers...........Codey

Thanks so much guys. I'm going to try to answer all of you in one post instead of replying individually.

The picture shows the automatic control switch which sits on top of the motor pump-there's no rotating parts in the plastic chamber (the white coloured part+cone thingy).

I think you guys may be right in that it may be a flow switch-because I can't explain the function of the long cylindrical cone thing if not for uniformly distributing pressure of the water to some detector that I cannot see. And also what is the point of the chamber if not for increasing the pressure and containing it. Also, the cylindrical thing extends into the circuit area but doesnt physically touch.

I'm going to try to expose the circuit board and take some proper photos tonight.

Yeah, I've tried pressing the reset button etc but there's no response.

The water is connected to the council mains. From the photos I will post tonight, you will see that there is a 6 inch (main) pipe that comes from somewhere (im guessing the council supply) and then its split up into 23 smaller 1-inch pipes (one for each floor) with the water meter on each one. So hopefully, there's no health problems there?

We're living on the top floor (23rd floor) of this apartment building. Apparently it is a common problem in older Hong Kong buildings to have poorer water pressure on the top floor. I don't know what the reason for that is. Like, why do we need a pump but the 22nd floor does not? Does it have something to do with my 1-inch pipe being split into two (one for the house and one for the tap for my washing machine on the roof?) I don't see how this would lower the pressure if the original main pipe was split into 23.

Thanks again you smart people!

Daniel

I look forward to the photos. The water pressure off the main is dependant on the pressure in the supply line, however some places will have a water tower some distance away ( preferably on a hill) that is filled with water. From this tower, which is normally 20-30 meters high, the water is gravity fed to the surrounding suburb. The water pressure is equal to the gravity x the height. Thus if, for arguments sake, your 22 nd floor is on the same level as this tower, the pressure may be acceptable but the 23rd and higher floor will feel the difference. Your pressure may only be 1 millibar bar, which will give you a little flow but no pressure at all. The pump will ensure that all floors will have the same pressure ( or nearly, since the height from the pump will have an effect.

yeah apparently this is a common problem in hong kong for people who live on the top floor. the extra floor makes all the difference in pressure head. and thus explains why we have a pump and other people do not...haha

but atleast we've narrowed the problem to something wrong with the switch.

NBHM,

Well as I said before, if the reset button does not start the pump and run it for at least 10-15 sec , then the flow control switch is Faulty and you will need to replace it (unless you can repair it..?).

There are no moving parts except for a sort of plunger attached to what you see as a cone. The cone/bladder thing is an expansion chamber. it does not boost anything. The pump boosts the pressure and this device allows the system to have a small reserve of water at the maximum pressure developped by the pump (That is the reason for the 15 sec running timer after the taps have been closed...). The plunger or spindle... is attached to it and moves with the pressure being developped. When the tap is opened, the outrush of water from this reservoir will allow the plunger to move again and, depending on the setting of its length, closes a circuit (either by physical contact or sensor) to start the pump on low pressure in the system.

When the pump is running, another device (electronic...) will detect water movement and keeps the pump running until nowater is detected moving, then 15 sec extra...

If the pump runs for a short time after pressing the reset, then maybe it is possible to make some adjustment for it to operate properly. Otherwise better replace the unit.

Hi newbiehandyman,

Quite coincidentally yesterday I received one of those many unsolicited promo email for equipment from China, but this one offered a pump switch identical to yours. In case you might want to chase some aspects you will find it here.

http://ailisheng.bossgoo.com/product-Pressure-Switches/Electronic-Pressure-Control-840915.html

Not a lot of technical info and can't find the actual OEM, it seems to be promoted by those B2B/trading websites, and the the only known details seem to be;

TECHNICAL PARAMETERS:

HYSK102

TECHNICAL PARAMETERS: Rated voltage:220-240v, 110-115v frequency:50/60Hz MAX.current:10(6)A Protection grade:IP65 Starting pressure setting:1.0bar or2.2bar

Good luck and hope this may help.

Bob,

referring to my previous contributions, The specs you got from the chinese site mean:

- They supply two models: One set at 1.0 bar and the 2nd is set at 2.2 bar--> these are the minimum pressures that will trigger the switch to stat the pump whenever the water pressure, in front of the switch, reaches them or less.

- The other specs mentioned are self-explamatory.

Just a little help from a maintenance man. Pressure pumps for buildings (and cities) cycle, sometimes the pressure on the top floor will be low, sometimes it may rise.

First, I would install a good pressure gauge on the line and watch it for a day, seeing what is your highest pressure. If you see a big difference, a pressure tank with a check valve will hold the high pressure for your use. No pumps, no controls, just a tank and a check valve between the tank and the supply. For the volume in the tank, you will have higher pressure. Even if the city pressure stops, you will have pressure.

Hi Dan,

The control switch okay but when your pump have an air trap it will never start because i have this kind of unit in our plant for our utility water use. This switch is for pressure when you open your tap the pump start automatically.